| 摘要 |
A predetermined current frequency is selected for a cable modem or embedded media terminal adapter to evaluate for presence of a CMTS signal. A determination is made whether the current frequency carries signal energy as opposed to just noise. If no signal energy is detected,the current frequency is changed by ½ of a channel width to a new frequency, which becomes the current frequency,and the determination is re-performed. If the determination of the current frequency indicates that signal energy is present,but not CMTS energy,then a new frequency indicates that selected that differs from the current frequency by 1 MHz. If the determination at the current frequency indicates that CMTS signal energy is present, but QAM lock cannot be achieved, then a new frequency is selected by changing from the current frequency by a full channel width. |
